Specifications

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Cisco 7100 Series VPN Router Installation and Configuration Guide
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Chapter 4 Performing a Basic Startup Configuration
Configuring a Router
(See Table 4-3 for a list of commands used to change the default settings. Also see Table C-17 on
page C-18 for information regarding data service unit [DSU] feature compatibilities.)
Note For more information on configuring interfaces, refer to the Cisco IOS Interface Configuration
Guide and the Cisco IOS Interface Command Reference publications. See “Related Documentation”
section on page xi for more information.
Step 4 Enable the interface.
Router(config-if)# no shutdown
Step 5 Press Ctrl-Z (hold down the Control key while you press Z) or enter end to exit configuration mode
and return to the EXEC command interpreter.
Step 6 Save the new configuration to NVRAM as follows:
Router# copy running-config startup-config
[OK]
(See the “Saving the Running Configuration to NVRAM” section on page 4-17. Also see the “Checking
the Interface Configurations” section on page 4-18 for examples of interface configurations.)
Configuring the E3 Interfaces
The Cisco 7120-E3 provides one and the Cisco 7140-2E3 provides two high-speed, synchronous serial
ports that support full-duplex operation at E3 (34-Mbps) speeds. The default settings and the commands
to change the defaults are listed in Table 4-4.
Perform a basic interface configuration using the procedure below.
Note Additional configuration commands may be required, depending on your system requirements and the
protocols you plan to route on the interface.
Table 4-4 E3 Interface Defaults
Attribute Default Value Command
Clock source Line clock source
DSU bandwidth 34010 dsu bandwidth kbps (22 to 34010)
DSU mode 0 dsu mode {0 | 1}
National bit 0 national bit {0 | 1}
Scramble Not enabled scramble
no scramble
Framing G.751 framing {bypass
1
| g751}
1. If you use the bypass option, scrambling must be set to the default, disabled; the DSU mode must be set to the default,
0; and the DSU bandwidth must be set to the default, 34010.
Cable length 10 feet cablelength feet (0 to 450)
CRC 16 bits crc size (16 or 32 bits)